Main memory: ram and rom

The main memory of a computer is also called the 'immediate access store', as distinct from any storage memory available on disks. ______: RAM and ROM, both contained in electronic chips connected to the main board of the computer.

RAM stands for 'random access memory' and is the working area of the computer, that is, the basic location where the microprocessor stores the required information. It is called 'random access' because the processor can address with equal speed, instead of looking for the data in sequential order.

____________ , so it is lost when the machine is turned off. Therefore, if we want to use this information later on, we have to save it and store it on a disk. When running an application, the microprocessor finds its location in the storage device (the floppy or hard disk) and transfers a temporary copy of the application to the RAM area. Consequently, _________ if we want to increase the performance of a computer when several applications are open at the same time or when a document is very complex.

The RAM capacity can sometimes be expanded by adding extra chips. These are usually contained in single in-line memory modules or SIMMs, which are installed in the motherboard of the computer.

We can designate a certain amount of RAM space as a cache in order to store information that an application uses repeatedly. A RAM cache may speed up our work, but it means that we need enough internal memory or a special cache card.

ROM is an acronym for 'read only memory', which implies that the processor can read and use the information stored in the ROM chip, but cannot put information into it._______ , including instructions and routines for the basic operations of the CPU. These instructions are used to start up the computer, to read the information from the keyboard, to send characters to the screen, etc. They cannot be changed and are not erased when the power is turned off. For this reason, the ROM section is also referred to as firmware.

 B.  As we have seen, there are three types of memory used by computers: RAM, ROM and secondary storage. Look through this list of features and decide which type of memory they refer to.

a) RAM              b) ROM             c) secondary storage

1.	Any section of the main memory can be read with equal speed and ease.
2.	It is available in magnetic, optical and video disks.
3.	A certain amount of this memory can be designated as 'cache' memory to store information in applications that are used very frequently.
4.	It stores basic operating instructions, needed by the CPU to function correctly.
5.	Memory which can be expanded by adding SIMMs of 8 MB, 16 MB, 32 MB or other major increments.
6.	Information is permanent and cannot be deleted.
7.	You can save and store your documents and applications.